Unique Water Body Research Articles

A Dynamic Estuarine Classification of the Vertical Structure Based on the Water Column Density Slope and the Potential Energy Anomaly

The aim of this work is to develop a new estuarine classification attending to their vertical structure by examining the advantages and disadvantages of the existing classifications. For this purpose, we reviewed the main classifications, finding that most of them analyze the entire estuary as a unique water body without considering the spatiotemporal variability of the mixing zone in estuaries. Furthermore, the proposed classifications require the calculation of parameters that are not easily measurable, such as tidal current amplitude. Thus, we developed a new classification based on density profile slopes of the water column, which has been correlated to the potential energy anomaly. To test this classification, the proposed method was applied to the Suances estuary (Spain) during the year 2020 and to analyze the potential estuarine modifications under four climate change projections (RCP 4.5 and 8.5 for the years 2050 and 2100). To carry out this study, a calibrated and validated high-resolution horizontal and vertical 3D model was used. The application showed a high variability in the vertical structure of the estuary due to the tide and river. According to the proposed classification, the well mixed category was predominant in the estuary in 2020 and tended to grow in the projections of climate change. As a result, the fully mixed and weakly stratified mixing classes were reduced in the projected scenarios due to a decrease of external forcing, such as river flow and sea level rise. Furthermore, areas classified as stratified tended to move upstream of the estuary.

The changes in iron ions concentration and organic matter composition during the surface microlayer membrane formation process in freshwater

The surface microlayer membrane (SMM) is a complex and unique water body ecosystem. The SMM has a significant effect on water quality and the water ecological system. However, despite the long-lasting interest in the SMM formation process and its environmental effect mechanism in freshwater, studies on it are still scarce. This paper studied the changes in iron ions concentration and organic matter composition during the SMM formation process. Our results revealed that the iron ions enriched in the SMM, at a concentration of up to 8.02 μg/mL, exist in the form of Fe3+. The main organic matter is polysaccharides and proteins in the SMM. Additionally, the microbial community structure revealed that the changes in iron ion morphology in water and the SMM was a significant association with the presence of Aeromonas and Zoogloea. The rapid enrichment process of iron ions and organic matter in the aquatic surface microlayer is involved in the rapid formation of early SMM. Obviously, these findings provide new insights and a basis for the SMM of freshwater.

Homewaters: A Human and Natural History of Puget Sound. By David B. Williams

“Homewaters” is a perfect title for this captivating book about Puget Sound, since its waters and surrounding landscapes have been the ideal home for so many–both humans and countless other species–over the years. David Williams has a clear, friendly style of writing, making the book an easy read for people of diverse backgrounds and experiences. He weaves together the history, geography, hydrology, ecology and anthropology of this unique waterbody, telling its story from ancient times to the present in a very personal and reflective way. The chapters build upon each other, each enriching our understanding of this special region and helping us to develop the relationships with the Sound that are essential for its future integrity. Williams takes us back to the chilly Pleistocene times and describes the profound changes that have taken place in the region over the millennia: the influence of volcanoes, sea level fluctuations, the way the Sound’s topography directs the currents and the mixing of fresh and salt water, and of course, the arrival of people and how their lives have changed over time. Citing contemporary Native Americans from the many nations whose territories surround the Sound, as well as archaeologists and historians, he explains how the First Peoples learned to survive and thrive in this beautiful place, their alliances with other communities through trade and intermarriage, and how they have endured and countered enemy attacks. He also explores the unique and effective ways Indigenous Peoples have developed for sustaining and enhancing the various resources of the region over countless generations.

Results of the hydrological, hydrochemical, biological and medico-hydrobiological studies of the Kuialnyk Estuary

The Kuialnyk Estuary belongs to the group of closed estuaries of the Northwestern Black Sea coast and is a unique water body of national importance with therapeutic properties. The natural territories of the Kuialnyk Estuary were declared as a resort of national importance and form a part of the Kuialnyk National Nature Park.
 The purpose of the research is to introduce the results of the hydrological, hydrochemical, hydrobiological and medico-biological studies of the condition of the Kuialnyk Estuary and seawater in the Odesa Bay that were conducted in 2021 and to compare them with the results of previous years. This would help to determine the conditions under which the estuary’s natural system is functioning, to ensure preservation and restoration of its natural resources, to prevent their pollution, clogging and depletion, as well as to identify changes of the natural resources of the Kuialnyk Estuary in the context of its artificial replenishment with seawater from the Odesa Bay and varying hydro-ecological factors.
 The general conclusion is as follows: replenishment of the estuary with seawater during the cold period of 2020-2021, increasing amount of atmospheric precipitation and decreasing rate of evaporation from the estuary’s water surface in 2021 raised the Kuialnyk Estuary’s water level. This led to significant improvement of the estuary’s hydro-ecological condition compared to 2020, however, because of its contamination with petroleum hydrocarbons, some toxic and polycyclic aromatic hydrocarbons, the water quality in 2021 is still assessed as satisfactory. The quality of the bottom sediments of the Kuialnyk Estuary from the environmental perspective is assessed as very poor because of their contamination with petroleum hydrocarbons, organochlorine pesticides and polycyclic aromatic hydrocarbons. The physicochemical composition of colloidal dispersions of the Kuialnyk Estuary’s peloids is barely different as compared to previous years. As per indicators of Eh (2017-2021) and pH (2020-2021), the quality of the peloids within the area used by the sanatorium did not meet the established conditions and the Medical (Balneological) Conclusion. Compared to 2020, the sanitary and microbiological condition of peloids improved in 2021, however, was still unsatisfactory. The characteristics of peloids’ biological activity during different periods of studies correlate with general mineralization fluctuations. Maintaining oil mineralization at a level not higher than 250 g/dm3 is quite important in order to preserve the unique deposit of natural healing resources of the Kuialnyk Estuary.
 Therefore, solving the following problems remains a priority: reducing the mineralization of the estuary’s water via increase of the rate of clean fresh water supply from various sources instead of using salty seawater; preventing the pollution from anthropogenic sources from entering the estuary (through water runoff from the watercourses flowing into the Kuialnyk Estuary such as the chute from the sandbar, Korsuntsivska and Hildendorfska gullies and others).

Heavy metals accumulation in fish, a growing threat in the Caspian Sea

Abstract: Water Pollution is a great concern all over the world specially in closed or semi-closed ecosystems like the Caspian Sea. Among the huge array of anthropogenic pollutants heavy metals have been responsible for several disastrous event damaging for aquatic biota and the man. Heavy metals enter the Caspian Sea through land-based oil exploration with over 100 years of history and offshore oil exploration which started 1950. Major rivers of the Caspian Sea watershed also have their share in ever increasing pollution in this unique water body. Fish are the main suspects of the pollution and sadly some of the unique specie of the Caspian Sea have already been vanishes extinct regionally or even globally and some are on the brink of extinction. Several studies conducted by authors and other researchers in the riparian countries of the Caspian Sea shows an increasing trend in heavy metal load via bioaccumulation and biomagnification in various tissues of sturgeons arguably the most valuable fish on the planet and also other bony fishes of great importance for local people and fishermen which rises health concern for fish itself and human. Strict measure should be taken and implemented to control and reduce heavy metal loads into water bodies in general and the Caspian Sea in particular. Strict measures should be taken and implemented under the observation of international organization to control od reduce heavy metal pollution in the Caspian Sea.

Ichthyofauna of the remarkably crystalline rio Pratinha, upper rio Paraguaçu basin, Chapada Diamantina, Brazil: inventory and conservation status

ABSTRACT The rio Pratinha is a short affluent of the upper course of the rio Paraguaçu basin inserted in the semiarid domain in the northeastern of Brazil. It is a unique water body with remarkably transparent water exiting from a cave and immediately forming a lagoon, which has whitish substrate partially covered by tiny gastropod shells. The local ichthyofauna is known only by a few descriptions of endemic or geographically restrict species. The inventory of the ichthyofauna performed herein revealed 24 species distributed in 22 genera, 13 families, and four orders. Characiformes and Siluriformes were the most representative orders, with 15 and eight species, respectively. Characidae is the most rich-species family. In the last decades the rio Pratinha is suffering great environment alteration due the intense anthropic activity focused on touristic exploration, with consequences on its ichthyofauna. Three endemic of the rio Pratinha or rare species occurring therein are currently defined as threatened of extinction: Astyanax brucutu, Kolpotocheirodon figueiredoi, and Lepidocharax diamantina. Furthermore, some previously abundant species in the river, such as A. brucutu and Hyphessobrycon negodagua, are now rarely observed or present in recent samplings. The non-native species Coptodon rendalli and Poecilia reticulata also occur in the river.

Analysis of a Tropical Warm Spring Microbiota Using 16S rRNA Metabarcoding

The Ikogosi Warm Spring is a unique ecological niche in Western Nigeria with an average temperature and pH of 38°C and 5.8 respectively. It mixes with an adjacent cold spring (28°C & pH 7.6), about 100 meters from source, yielding a confluence body of water of 32°C and pH 7.7. To explore the bacterial community structure of this uncommon environment and to scan for potentially useful bacteria, metagenomes extracted directly from five samples (source and mid-point of warm spring; source and midpoint of cold spring, and the confluence) were analyzed. Using the MiSeq Illumina next generation sequencing protocols, the V3-V4 region of the 16S rRNA gene pool was sequenced and analyzed by QIIME (Quantitative Insights into Microbial Ecology) and R software. At least 11% (47,446) of all the sequences were unknown to any of the databases employed. Bacterial diversity and abundance at the source of both springs were extremely low, accounting for less than 0.07% of the total sequence reads at the confluence, 100 m downstream. In contrast to the highly diversified mesophilic confluence community where 21 different phyla were identified, only 4 and 5 phyla were recovered from the source-point of the warm spring and cold spring respectively. The most prevalent phyla in all samples were members of the versatile Proteobacteria (35% - 50% relative abundance), and the hardy Firmicutes (33% - 40%). Operational taxonomic units (OTUs) obtained from all the samples averaged at 1414. Temperature and pH were equally significant predictors of genomic diversity and richness, with the warm and cold spring sources having less than 5 bacteria phyla. Exiguobacterium sp. (a potential plastic degrader) and other deep rooted bacteria were found in the warm spring while the cold spring outflow contained among others such as Rubrobacter sp. and Chloroflexi sp. (which is close to the phylogenetic root of the domain Bacteria). Many taxonomically unresolved sequences could indicate the presence of potentially novel bacteria in this unique body of water and underscores the need to systematically mine these rare genetic reservoirs for biotechnological applications. Moreover, such tropical hydrothermal ecosystems could contain some unknown primitive bacteria at the origins of life.

Around Baikal: on the causes of ecological problems

This paper is devoted to the unique water body, Lake Baikal, the largest freshwater reservoir by volume in the world that was included on the list of UNESCO World Heritage Sites and is regulated by the federal law of its protection. The global role of Baikal as a strategic reserve of water resources of the highest class is increasing in importance. Furthermore, Lake Baikal and its surroundings are invariably the focus of ecological problems. The most challenging issues are the lake’s water pollution leading to changes in hydrobiocenoses, soil and vegetation digression in areas of increased recreational load, forest fires causing a decrease of the number of rare species of flora and fauna, etc. Imperfection of the legal framework, the lack of a unified managerial center and the attempts to deal with the problems solely at the federal level involve a number of incompetent decisions on the lake level regulation and on the setting of its water-protection zone. The conflicts of the interests of the subjects of the federal and regional levels in issues related to use and the protection of natural resources present serious obstacles to the development of a unified, ecologically oriented strategy of economic development of the territory. For a successful solution of the current challenges it is necessary to recognize the ecological problems of Lake Baikal as the priority concerns throughout the country, optimize management of the socio-economic development of the Baikal natural territory on the basis of nature-conservation principles by ensuring appropriate funding, develop a unified scheme of comprehensive monitoring of the ecological and sanitary-hygienic status of Lake Baikal and its protection zone, improve the system of scientific research on the Baikal natural territory, introduction ubiquitous ecological training and education of the population, organize the waste and effluent treatment system in accordance with the latest international technologies, etc.

Potential Role of Groundwater in Pollution of Coastal Water of the Caspian Sea by Organic Pollutants

The place and potential role of groundwater in the Caspian Sea coastal water pollution is predicted for the first time with the use of synthetic analysis and the generalization of literature data on the Azerbaijan national groundwater, pathways, and mechanisms of its pollution and fundamental concepts and principles developed by landscape geochemistry. The findings show that the groundwater, which may absorb a given amount of organic pollutants from the soil surface (including the sites of oil exploration enterprises), can potentially carry them into the Caspian Sea waters, polluting it; consequently, along with the surface runoff of these pollutants, it can have an adverse impact on the ecology of this unique water body.

Coral reefs of the Red Sea — Challenges and potential solutions

The Red Sea is a unique body of water, hosting some of the most productive and diverse coral reefs. Human populations along coasts of the Red Sea were initially sparse due to the hot and arid climate surrounding it, but this is changing with improved desalination techniques, accessible energy, and increased economic interest in coastal areas. In addition to increasing pressure on reefs from coastal development, global drivers, primarily ocean acidification and seawater warming, are threatening coral reefs of the region. While reefs in southern sections of the Red Sea live near or above their maximum temperature tolerance and have experienced bleaching events in the recent past, coral reefs in northern sections are considered a coral reef refugia from global warming and acidification, at least for the coming decades. Such differential sensitivities along the latitudinal gradient of the Red Sea require differential solutions and management. In an effort to identify the appropriate solutions to conserve and maintain resilience of these reefs along a latitudinal gradient, we used a SWOT analysis (strengths/weaknesses/opportunities/threats) to frame the present situation and to propose policy solutions as useful planning procedures. We highlight the need for immediate action to secure the northern sections of the Red Sea as a coral reef climate change refuge by management and removal of local stressors. There is a need to strengthen the scientific knowledge base for proper management and to encourage regional collaboration on environmental issues. Based on scientific data, solutions such as marine protected areas, fishing regulation, and reef restoration approaches were ranked for five distinct latitudinal sections in the Red Sea and levels of interventions are recommended.

The dispersion-confinement mechanism: Phytoplankton dynamics and the spring bloom in a deeply-mixing subtropical sea

The spring phytoplankton bloom is a major, extensively studied phenomenon in temperate oceans. Much less is known about blooms in subtropical seas. Yet, even in temperate seas the processes determining the initiation of the bloom and the phytoplankton dynamics during the preceding mixed-layer deepening are still debated. Here we assess the validity of two bloom-initiation mechanisms, previously proposed for temperate oceans, for the case of the subtropical oligotrophic Gulf of Aqaba (northern Red Sea): the Critical Depth Hypothesis and the Dilution-Recoupling Hypothesis. The Gulf is a unique water body, where convective mixing during winter reaches hundreds of meters in depth, entraining nutrients that support conspicuous spring blooms. Our study is based on a long time series of oceanographic and meteorological parameters complemented with experimental measurements of grazing rates. We show that neither the Critical Depth nor the Dilution-Recoupling hypotheses explain the phytoplankton dynamics during the winter and spring in the Gulf. Instead, we suggest that the phytoplankton dynamics is governed by a “Dispersion-Confinement Mechanism”. During winter, phytoplankton cells that photosynthesize and grow in the upper (illuminated) layer are homogeneously dispersed by vertical mixing. Thereby the deepening of the mixed layer leads to the dilution of the cells with plankton-free water from below, which together with grazing, maintain their relatively low concentration. Once mixing stops, the cells are no longer vertically dispersed, allowing their accumulation in the upper layer and, in turn, the development of the spring bloom. High specific growth rates, necessary to maintain the increase of the entire (integrated) phytoplankton biomass during the deepening of the mixed layer (the “Dispersion Phase”) as well as supporting their rapid growth during the bloom (the “Confinement Phase”) are possible due to the entrainment of nutrients by deep vertical mixing. Although this mechanism is proposed here for the case of a nutrient-limited oligotrophic sea, its relevance for temperate oceans deserves further consideration.

Withdrawn: The Dispersion-Confinement Mechanism: Phytoplankton dynamics and the spring bloom in a deeply-mixing subtropical sea

Abstract The spring phytoplankton bloom is a major, extensively studied phenomenon in temperate oceans. Much less is known about blooms in subtropical seas. Yet, even in temperate seas the processes determining the initiation of the bloom and the phytoplankton dynamics during the preceding mixed-layer deepening are still debated. Here we assess the validity of two bloom-initiation mechanisms, previously proposed for temperate oceans, for the case of the subtropical oligotrophic Gulf of Aqaba (northern Red Sea): the Critical Depth Hypothesis and the Dilution-Recoupling Hypothesis. The Gulf is a unique water body, where convective mixing during winter reaches hundreds of meters in depth, entraining nutrients that support conspicuous spring blooms. Our study is based on a long time series of oceanographic and meteorological parameters complemented with experimental measurements of grazing rates. We show that neither the Critical Depth nor the Dilution-Recoupling hypotheses explain the phytoplankton dynamics during the winter and spring in the Gulf. Instead, we suggest that the phytoplankton dynamics is governed by a “Dispersion-Confinement Mechanism”. During winter, phytoplankton cells that photosynthesize and grow in the upper (illuminated) layer are homogeneously dispersed by vertical mixing. Thereby the deepening of the mixed layer leads to the dilution of the cells with plankton-free water from below, which together with grazing, maintain their relatively low concentration. Once mixing stops, the cells are no longer vertically dispersed, allowing their accumulation in the upper layer and, in turn, the development of the spring bloom. High specific growth rates, necessary to maintain the increase of the entire (integrated) phytoplankton biomass during the deepening of the mixed layer (the “Dispersion Phase”) as well as supporting their rapid growth during the bloom (the “Confinement Phase”) are possible due to the entrainment of nutrients by deep vertical mixing. Although this mechanism is proposed here for the case of a nutrient-limited oligotrophic sea, its relevance for temperate oceans deserves further consideration.

О необходимости изучения и охраны памятника природы «Чегемские водопады»

The paper presents the Chegem waterfalls (a unique water body, a specially protected natural territory of the Republic of Kabardino-Balkaria) main characteristics. Significance and urgency of the integrated researches of the Chegem waterfalls natural phenomena have been demonstrated and a set of measures to protect and study this specially protected natural territory has been proposed.

Dilution of pollution? Processes affecting the water quality in the river-style Three Gorges Reservoir

The Three Gorges Reservoir (TGR) in the Yangtze River is a unique water body. There is no comparative river-style reservoir in the world with similar characteristics and magnitudes of shape, size, water level fluctuation, and discharge. This highly dynamic system is located in a rapidly developing area of China covering parts of the Hubei Province and Chongqing Municipality. Increasing efforts for waste water treatment and pollution management can hardly compete with growing urban areas, industry, and infrastructure. Thus, huge amounts of various pollutants enter the TGR water bodies through point and non-point sources. Serious eutrophication problems manifest themselves in increasing numbers of algal blooms, especially in tributary backwaters of TGR. Besides nutrient loads, absolute concentrations of anthropogenic pollutants like heavy metals and organic chemical compounds rarely reach critical levels according to the Chinese, German, and WHO water quality guidelines. The massive dilution of these compounds in the mean discharging water of around 30,000 m 3 /s causes low absolute concentrations. But overall, tremendous total loads are transported further downstream and may remain a threat to connected ecosystems. At Tongji University in Shanghai, China, the 3rd conference entitled “Workshop on Processes in the Yangtze River System” was held for scientific exchangeon the recent cutting edgeenvironmentalresearchintheYangtzeRiverwithafocus

A Great Salt Lake Problem

AN alluring possibility has for a long time attached itself to the economic resources of Great Salt Lake, in the Western United States, in the way of establishing in its waters, as permanent residents, forms of marine life of commercial importance. The United States Fish Commission recently, made an examination of the lake with a view to determining the feasibility of such a plan. The work was undertaken by Mr. H. F. Moore, of the Commission, who finds in the peculiarly interesting conditions which prevail in this unique body of water a decisive answer.

On making saltpetre France, and in Spain

The Red Sea is a unique body of water, hosting some of the most productive and diverse coral reefs. Human populations along coasts of the Red Sea were initially sparse due to the hot and arid climate surrounding it, but this is changing with improved desalination techniques, accessible energy, and increased economic interest in coastal areas. In addition to increasing pressure on reefs from coastal development, global drivers, primarily ocean acidification and seawater warming, are threatening coral reefs of the region. While reefs in southern sections of the Red Sea live near or above their maximum temperature tolerance and have experienced bleaching events in the recent past, coral reefs in northern sections are considered a coral reef refugia from global warming and acidification, at least for the coming decades. Such differential sensitivities along the latitudinal gradient of the Red Sea require differential solutions and management. In an effort to identify the appropriate solutions to conserve and maintain resilience of these reefs along a latitudinal gradient, we used a SWOT analysis (strengths/weaknesses/opportunities/threats) to frame the present situation and to propose policy solutions as useful planning procedures. We highlight the need for immediate action to secure the northern sections of the Red Sea as a coral reef climate change refuge by management and removal of local stressors. There is a need to strengthen the scientific knowledge base for proper management and to encourage regional collaboration on environmental issues. Based on scientific data, solutions such as marine protected areas, fishing regulation, and reef restoration approaches were ranked for five distinct latitudinal sections in the Red Sea and levels of interventions are recommended.